JPH0160208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is equipped with a wheel elevation control valve that detects an increase in the ground load of a sensor float and automatically and reversibly lowers the propulsion wheels using a hydraulic mechanism. A human operating device is provided that can be switched and held between an automatic control position that operates forward and reverse in conjunction with the ground pressure detection of the sensor float, and a wheel upward check position that only allows the downward operation of the automobile wheels and prevents the automatic wheel upward operation. Regarding walking rice transplanters.

The above-mentioned walk-behind rice transplanter is capable of planting seedlings by forcibly lowering the wheels, raising the seedling planting device, and moving the human operating tool to the wheel raising check position when driving on the road or interrupting planting work. In addition to maintaining the raised position of the seedling planting device and preventing it from coming into contact with the road surface or muddy surface, when the vehicle body turns, it is possible to use the raised position of the wheels to prevent the seedling planting device from coming into contact with the road surface or muddy surface. The device artificially increases the ground load of the sensor float to raise the seedling planting device to an appropriate position, and maintains that raised position so that it can be rotated without mud being pushed by the side floats. It was hot. However, in conventional systems, when the wheel rise restraining position is used for vehicle body turning, the vehicle body may become unstable every time the sensor float touches the ground mid-turn due to unevenness of the mud surface or pitching of the vehicle body during turning operations. Due to the automatic, irreversible rise, the height of the steering wheel and the vehicle body from the ground becomes too high, making it difficult to perform turning operations.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional situation, an object of the present invention is to improve the wheel lifting/lowering operation structure so that turning operations of a vehicle body can be performed more easily and smoothly.

A characteristic configuration of the present invention is that, in the above-mentioned walk-behind rice transplanter, the human operating tool is operated to lower the automobile wheels and at a speed lower than the normal wheel rise speed, separately from the automatic control position and the wheel rise restraining position. It is provided so that it can be switched to an automatic control position for turning, which allows the vehicle wheels to rise.

In other words, the automatic control position for turning that allows lowering of the vehicle wheels based on sensor float detection and raising of the vehicle wheels at a lower speed than the normal wheel raising speed is replaced by the wheel raising check position that was conventionally used for turning operations. By providing this separately, when the vehicle turns, it is possible to artificially increase the ground load of the sensor float by, for example, pulling up the handle a little while the human operating tool is operated to the automatic control position for turning. After being automatically raised, the vehicle body can be automatically lowered at a slow speed, so the height of the vehicle body above the ground can be maintained high for a relatively long period of time, and the vehicle body can turn smoothly and without mud pushing due to side floats. While making it easy to perform the maneuver, the automatic slow lowering of the vehicle body also suppresses the excessive automatic rise of the vehicle body due to the sensor float touching the ground mid-turn due to unevenness of the mud surface or pitching of the vehicle body.
The height of the vehicle body above the ground and the height of the handlebars can be maintained within a range that makes it easy to perform turning operations, making the turning operation of the vehicle even smoother and easier. We have now been able to provide a model rice transplanter.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in Fig. 1, a pair of left and right propulsion wheels 1
A driving unit 3 is provided at the front of the machine frame 2, which is equipped with a tilted seedling tray 4 that moves back and forth horizontally with a constant stroke, and seedlings are taken out one by one from the seedling tray 4 and planted on a mud surface. Seedling planting device 7 equipped with various devices such as a plurality of seedling planting claw devices 5 and two side floats 6 arranged on the left and right outside of the machine body.
are connected to the rear of the fuselage frame 2, and further connected to the fuselage frame 2 are a pair of rearwardly extending control handles 8 on the left and right, and a front center float 9 that can swing freely around a horizontal axis _X1 at the front end. It is constructed as a walking rice transplanter.

The pair of left and right propulsion wheels 1 are configured to be able to be raised and lowered by integrally driving and vertically swinging the pair of left and right wheel transmission cases 10 that support the wheels 1, and the raising and lowering operation structure will be described below. As shown in FIGS. 2 and 3, the wheel transmission case 10 controls the control valve 12 of the hydraulic cylinder 11 for driving and swinging, and supplies pressure oil from the pump 13 to the hydraulic cylinder 11 to swing the wheel transmission case 10 downward. a neutral state in which pressure oil is confined in the hydraulic cylinder 11 and the swinging of the wheel transmission case 10 is fixed; a neutral state in which the oil returned from the hydraulic cylinder 11 is given throttle resistance and the wheel transmission case 10 is loosened by the weight of the vehicle body; It is possible to freely switch between a state in which the wheel transmission case 10 is swung up and swung at a relatively high speed, and a state in which the return oil from the hydraulic cylinder 11 is directly communicated with the tank 14 and the wheel transmission case 10 is swung up and swung at a relatively high speed due to the weight of the vehicle body. One end of an L-shaped arm 16 configured as a swinging spray type four-position switching valve and supported swingably around its axis on a horizontal support shaft 15 fixed to the machine body, and a spool operating tool 12a of the control valve 12. When the other end of the L-shaped arm 16 swings upward, the spool of the control valve 12 is slid toward the downward swinging side of the wheel transmission case 10, and the other end of the L-shaped arm 16 swings downward. The spool of the control valve 12 is connected via the link 17 so that the spool of the control valve 12 is slidably operated toward the upward swinging side of the wheel transmission case 10 when the wheel transmission case 10 moves, and is supported to swing freely around the front end horizontal axis _X1 . The swinging rear end of the front center float 9 and the other end of the L-shaped arm 16 are removed from the front center float 9 due to excessive movement of the rear end of the front center float 9 caused by riding on a mud lump or the like on the mud surface. A downward pressure force is applied to a receiving member 19 which is interlocked and connected via a rod 18 with a swing absorption mechanism and which is fixedly attached to the side of the L-shaped arm 16 connected to the rod 18. A ground load setting spring 20 is provided to urge the center float 9 to press against the ground.

In other words, when the hard plate becomes deep and sinks into the mud of the wheel 1 during traveling work, the front center float resists the ground load setting spring 20 due to the corresponding increase in the ground load of the front center float 9. By the upward swinging of the rear end of the float 9, the control valve 12 is operated via the rod 18 and the L-shaped arm 16 to the downward swinging side of the wheel transmission case 10, that is, to the downward swinging side of the wheel 1, and the front center float 9 is grounded. The wheels 1 are automatically lowered until the load returns to the set value, and if the hard plate becomes shallow and the ground load of the front center float 9 decreases below the set value, the front center float 9 is lowered by its own weight. Due to the downward swinging of the rear end, the control valve 12 is operated via the rod 18 and the L-shaped arm 16 to the upward swinging side of the wheel transmission case 10, that is, to the upward swinging side of the wheel 1, thereby lowering the ground load on the front center float 9. The wheel 1 is configured to automatically rise until the value returns to the set value.

To explain further, the front center float 9 is configured to double as a ground load detection sensor, and based on the detection result, the height of the seedling planting device 7 from the ground is maintained within an appropriate range according to changes in the depth of the hardboard. The wheels 1 are configured to be automatically raised and lowered.

Furthermore, these wheels 1 are configured to be capable of being manually raised and lowered in addition to the above-mentioned automatic raising and lowering operation, and the structure of the manual raising and lowering operation will be described in detail below. As shown in FIGS. 3 and 4, a restraining arm 21 integrally formed with an abutment locking portion 21a for the lower surface of the connecting side portion of the rod 18 of the L-shaped arm 16 is attached to the horizontal support shaft 15 with its axis. A lever guide hole 2 is formed in an operation box 22 attached to the control handle 8, and is swingably supported around the control handle 8.
3, wheel automatic elevation control position A, wheel automatic elevation control position D ₁ during rotation, wheel automatic elevation check position
A swingable operating lever 24 is provided between D ² and the wheel forced lowering position U, and when the operating lever 24 is operated to the wheel automatic elevation control position A, the check arm 21 is brought into contact with the control lever 24. The stop portion 21a is largely separated downward from the lower surface of the L-shaped arm 16 in the neutral state, and the check arm 21 is held in the swinging position by the biasing force of the attached spring 25 in this state, and the control valve 12 is fully switched. In order to allow the L-shaped arm 16 to swing up and down throughout the operating arrangement,
In addition, when the operation lever 24 is operated to the wheel automatic elevation control position D ¹ for turning, the contact locking portion 2
1a is slightly detached downward from the lower surface of the L-shaped arm 16 in the neutral state, and the check arm 21 is moved against the spring 25 due to the locking action between the lever 24 and the engaging portion 23a of the lever guide hole 23. The control valve 12 is further operated so as to come into contact with and prevent the downward swinging of the L-shaped arm 16 for switching the control valve 12 from the wheel slow speed increase state to the wheel normal speed increase state. As the lever 24 is operated to the wheel automatic lift check position D ² , the abutment locking portion 21 a comes into contact with the lower surface of the L-shaped arm 16 in the neutral state, and the lever 24 and the lever guide hole 2 are brought into contact with each other.
3, the check arm 21 swings and is fixed in that state against the spring 25 by the locking action with the engaging portion 23a of the L-shaped arm 16, and prevents the L-shaped arm 16 from swinging downward from the neutral position, thereby closing the control valve. Furthermore, as the operating lever 24 is operated to the wheel forced lowering position U, the L-shaped arm 16 of the abutment locking portion 21a is moved so that the operation of the wheel 12 toward the upward side is prevented.
The L-shaped arm 1
The control lever 24 and the check arm 21 are moved so that the control valve 12 is forcibly operated to the wheel lowering side by upwardly swinging the control valve 12 integrally with the check arm 21.
are interlocked and connected by a wire 26. Furthermore, when the operating lever 24 is in the automatic wheel elevation control position A, a planting clutch (not shown) for intermittent power transmission to the seedling platform 4 and the seedling planting claw device 5 is connected to the operating lever 24. The planting clutch is interlocked so that it is in the engaged state, and the L-shaped arm 1
6 to the receiving member 19 of the front center float grounding load setting spring 20, and a state in which the spring biasing action is permitted. Freely movable spring operating swing member 27
and the operating lever 24 are interlocked and connected by a wire 28 so that the swinging member 27 is in the state where the spring biasing action is allowed only when the operating lever 24 is in the automatic wheel elevation control position A, similar to the planting clutch. be. That is, when traveling for planting, the operation lever 24 is operated to the wheel automatic lift control position A to engage the planting clutch, and as described above, the front center float 9 is operated as a ground load detection sensor to plant seedlings. In order to maintain the attachment device 7 at an appropriate working height above the ground, and when stopping the vehicle or driving on the road, operate the operating lever 24 to the wheel forced lowering position U and disengage the planting clutch.
Raise the seedling planting device 7 and the machine to an appropriate height,
Then, by subsequently operating the operating lever 24 to the wheel automatic lift check position ^D2 , the automatic lift of the wheels 1 based on the detection result of the front center float 9 is checked, and the seedling planting device 7 and the machine body rise. condition, and avoid contact between the seedling planting device 7 and the front center float 9 with the road surface or mud surface.
Furthermore, when turning the aircraft during planting work,
Operate the operating lever 24 to automatic control position D ¹ for turning, disengage the planting clutch, set the wheels 1 to the normal speed automatic increase check state, and in that state pull up the control handle 8 slightly to move the aircraft slightly forward. A ground load is artificially applied to the front center float 9, which is in a floating state by tilting and releasing the biasing action of the ground load setting spring 20, to raise the aircraft, and subsequently, the front center float 9 Based on the detection result, the machine is operated to turn while slowly automatically raising the wheels 1, and by this wheel slow and automatically raising function, the height above the ground of the machine and the seedling planting device 7 is maintained high for a relatively long period of time. This allows the aircraft to turn smoothly and lightly without mud pushing by the side floats 6, and prevents excessive aircraft turning caused by the front center float 9 touching the ground mid-turn due to pitching of the aircraft, etc. The automatic lift is suppressed to maintain the height of the aircraft above the ground and the height of the control handle 8 within a range that makes it easy to perform turning operations.

The specific control structure for automatically switching the control valve 12 based on the detection of the ground load of the front center float 9 as a sensor float can be changed in various configurations, and the In order to achieve low-speed vehicle wheel lifting operation, instead of providing a separate port with a throttling function in the control valve 12, the wheel lifting port may be configured to restrict its operating position to a half-port state. The mechanism for slowly raising the wheel 1 can be modified in various ways.

Further, various configuration changes can be made to the wheel slow speed raising mechanism and the specific interlocking structure between the control valve 12 and the human operating tool 24 such as the operating lever.

The present invention is directed to walking-type rice transplanters equipped with various types of wheel lifting mechanisms.

[Brief explanation of drawings]

The drawings illustrate an embodiment of the walking-type rice transplanter according to the present invention, in which Fig. 1 is an overall side view, Fig. 2 is a schematic hydraulic circuit diagram for wheel elevation, and Fig. 3 is a side view showing a wheel elevation control structure. FIG. 4 is an enlarged plan view of the operation box. 1...Wheel, 9...Sensor float, 11...
... Hydraulic mechanism, 12 ... Control valve, 24 ... Human operating tool, A ... Automatic control position, D ¹ ... Wheel upward check position, D ² ... Automatic control position for turning.

Claims (1)

[Claims] 1 Equipped with a wheel elevation control valve 12 that detects an increase in the grounding load of the sensor float 9 and automatically and reversibly lowers the propulsion wheel 1 using a hydraulic mechanism 11, and also controls the control valve 12 to control the grounding of the sensor float 9. An automatic control position A that operates forward and reverse in conjunction with pressure detection, and a wheel upward check position D that allows only the downward operation of the automobile wheels and prevents the automatic wheel upward operation ^.
A walk-behind rice transplanter is provided with a manual operating tool 24 that can be switched and held, and the manual operating tool 24 is set to a lowering operation of automobile wheels, separately from the automatic control position U and the wheel upward restraining position ^D2 . A walk-behind rice transplanter characterized in that the automatic control position _D1 for turning is switchable to enable automatic wheel raising operation at a lower speed than the normal wheel raising speed.